Phosphorylated surfactants as hydrotropes

ABSTRACT

The invention comprises compositions containing (A) an alkaline builder, and (B) a blend of 10 to 80% by weight of the blend of a nonionic surfactant of the formula R(CH2CH2O)xH, where R is alkoxy, alkyl substituted amino or alkyl substituted phenoxy group, x is an average number of 1 to 30, and 90 to 20% by weight of the blend of a hydrotrope of the formula R1(CH2CH2O)yR2 where R1 is phenoxy substituted with a C6-C10 alkyl group or R1 is a C10-C18 alkoxy group, y is an average number of 1 to 20, R2 is a terminal group at least 90% of such groups being primary phosphate groups in acid or salt form, the remainder, if any, being hydrogen.  Preferred alkaline builders are hydroxides, carbonates, silicates, phosphates or polyphosphates of sodium or potassium.  Preferably, the compositions contain 75 to 99-5% by weight of alkaline builder and 25 to 0.5% by weight of the blend.  Aqueous concentrates of the above compositions are specified, comprising 4 to 40% by weight of an alkaline builder, 0.5 to 40% of the blend, the solids content not exceeding 40% by weight.  R2 may also be a secondary, tertiary or complex polyphosphate group.  Specified hydrotropes include octyl-phenoxy polyethoxy phosphates and nonyl-phenoxy polyethoxy phosphates and specified non-ionic surfactants include octylphenoxy and nonyl-phenoxy ethylene oxide adducts, C13H27O(CH2CH2O)12H, t-C12- 15H25- 31 NHCH2CH2OH and t-C12- 15H25- 31NH(CH2CH2 O)10H.  Many other examples of hydrotropes and non-ionic surface-active agents are given and examples of both aqueous and non-aqueous compositions are specified.

United States Patent O 3,294,693 PHOSPHORYLATED SURFACTANTS AS HYDROTROPES Jean Dupre, Levittown, Pa, and David B. Fordyce,

Moorestown, NJ assignors to Rohm & Haas Company, Philadelphia, Pa, a corporation of Delaware No Drawing. Filed Mar. 12, 1965, Ser. No. 439,472

16 @iairns. ((11. 252-135) This application is a continuation-in-part of US. Ser. No. 266,834, which was filed on March 21, 1963, and Ser. No. 195,967, which was filed on May 18, 1962, both of which have been abandoned.

This invention relates to improvements in the art of cleaning objects, particularly those made of metal, glass, etc.

Broadly stated, the invention pertain to detergents composed of alkaline builders and surfactants.

An object of the invention is to provide a means for solubilizing polyethylene oxide non-ionic surfactants into builder solutions.

A further object is to provide homogeneous built liquid detergents and alkaline cleaners containing polyethylene oxide non-ionic and alkaline builders.

Alkaline cleaners are the most widely used means in industry for cleaning metal, glass, certain plastics, etc. In the metal-forming field, in particular, such cleaners are used to remove various types of soil such as cutting oils, grinding, buifing, stamping, and drawing compounds. The alkaline cleaning solution may be used for soaking, spraying, or electrolyti types of cleaning. Of these, the soaking or tank cleaning technique is most important because of its widespread use in industry.

In the soaking method of cleaning, the article to be cleaned usually is dipped in or slowly transported through a hot alkaline solution with little or no agitation present. The cleaning solutions employed generally are made up of materials consisting of between about 88 and 99 percent by weight of various alkalies, such as caustic soda, sodium metasilicate, sodium orthosilicate, soda ash, trisodium phosphate (TSP), tetrasodium pyrophosphate (TSPP), and tetrapotassium pyrophosphate (TKPP), and from about 1 to 12 percent by weight to a surfactant. Usually, the concentration of the cleaning materials (alkali plus surfactant) in the tank or bath is maintained between 0.5 and percent of the cleaning solution. Thus, the cleaning baths will contain from 0.005% to 1.2% surfactant and 0.5 to 10.0% of the alkaline builders.

If the surfactant employed is not thoroughly soluble in the hot alkaline solution, it will tend to oil out oraccumulate at the surface of the bath. There are a number of reasons why this is undesirable and why it is important to have the alkali and surfactant homogeneously dispersed throughout the bath. One objection is the fact that a layer of surfactant on the surface will tend to adhere to and thereby contaminate the otherwise cleaned object as it is withdrawn from the bath, and the thus-contaminated surfaces Will be difiicult to clean by the normal rinsing operations which follow.

Another objection is the poor bath life which results when the surfactant and alkali exist in separate phases. As oil, grease and other soils are caused to be separated from the part being cleaned in the tank, a scum-like layer tends to collect at the top of the bath. When the accumulation of scum becomes so great it tends to coat the otherwise clean part as it is withdrawn from the bath, it becomes necessary to skim the soil from the top of the bath. Each time this is done a considerable amount of the surfactant will be removed and, of course, this tends to lower the concentration of the effective cleaning agents in the bath to a point where the bath becomes unsatisfactory much sooner than it otherwise would if such losses would be minimized or eliminated.

Even if the soil scum is not skimmed off, there is a tendency to lose surfactant when it is present as a layer on top of the bath. As the parts being cleaned are withdrawn from the bath, they tend to drag out some of the liquid in the bath. When concentrated at the top, the surfactant naturally is removed in greater quantities than would be the case if it were uniformly dispersed throughout the bath.

Still another disadvantage of a non-homogeneous bath which contributes, to poor bath life is the poor soil capacity of the bath which results from a two-phase system. There is a greater tendency for the surfactant to accumulate in the oil (or soil) phase, and this reduces the concentration of the surfactant in the aqueous phase. Eventually, the lack of surfactant in the aqueous phase will require it to be replenished, and this will take place much sooner than if the system had been homogeneous during the cleaning operation.

An obvious solution to these various problems is to employ only surfacants which are soluble in hot alkaline solutions. Of course, solubility alone will not take the place of surfactant effectiveness, and, therefore, it will be necessary to provide a surfactant which also is a good cleaner.

One of the best-known and effective surfactants for metal cleaning and the like is the class known as nonionics. Particularly effective members of this class are the polyethylene oxide type non-ionics, such as Triton X- 100. However, the use of such non-ionics in hot cleaning solutions containing alkaline builders has the disadvantage that they are not completely soluble in such baths.

By means of the present invention, however, according to which an alkyl or alkylphenoxy polyethoxy phosphate is added to mixtures or solutions of alkaline builders and the alkoxy, alkylphenoxy and alkylamine polyethylene oxide type of non-ionic surfactants, complete solubilization takes place and a satisfactory cleaning bath results.

Thus, it is now possible to prepare clear, non-separating, single phase, alkaline cleaning baths containing the highly effective non-ionic surfactants and alkaline builders. By way of illustration, at normal use concentrations of about 0.1%, Triton X-lOO would be far above its cloud point in hot 5% caustic or mixed alkaline builders. This would cause the non-ionic to oil out on top of the bath. But, when an alkyl or alkylphenoxy polyethoxy phosphate is added in accordance with the present invention, Triton X becomes completely and readily soluble and effective in the alkaline solution.

A similar problem exists with respect to the preparation of built liquid detergents which will be commercially marketable. It would be desirable to use non-ionic surfactants in such formulations because they are excellent for almost all cleaning operations such as laundry, floor and wall cleaning, industrial maintenance, etc. However, liquid detergent concentrates with desired levels of alkaline builders cannot be made with non-ionic surfactants because the non-ionics will be above their cloud points in such concentrates, thereby resulting in the formation of two-phase systems. To illustrate this effect, with built liquid formulations using an adduct of alkylphenol and 10 moles of ethylene oxide as an example, as the concentration of tetrapotassium pyrophosphate (TKPP) is increased the cloud point is lowered. Above about 9% TKPP, the cloud point would be below 25 C., and this formulation would separate into two phases at room temperature. With most of the surfactant on top and the alkaline'builder in the bottom layer, the user will never know how much of each he is employing for any given application. Disuniform amounts of each will be employed each time with correspondingly unpredictable results.

By means of the present invention, it is now possible to prepare homogeneous, non-separating liquid detergents containing non-ionic surfactants, such as Triton X-100, and the desired levels of alkaline builders. Such formulations will assure the user that each portion which he employs will have a uniform composition, i.e., the desired ratio of surfactant to builder will remain constant throughout.

The compositions of the solubilizers or hydrotropes which are useful in the present invention are surfaceactive materials which contain upwards of 85% primary phosphate esters (i.e., monoester phosphate) components. These esters are members of the class consisting of the condensation product, and the salts of said condensation product, of the reaction of polyphosphoric acid and a compound having the formula R(CH CH O) H. In this formula R must be either an alkyl phenoxy group, the alkyl radical of which is in the range of C to C or an alkoxy group, the alkyl radical of which is in the range of C C and x is a number from 1 to 20.

The novel phosphate ester hydrotropes are prepared by a process disclosed in copending application Serial No. 255,173 (now U.S. Patent 3,235,627, issued February 15, 1966), which was filed on January 31,1963, by Richard C. Mansfield. (That application, incidentally, is a continuation-in-part of Serial No. 195,952, which was filed on May 18, 1962, and since abandoned.) The contents of the specifications of both those applications are incorporated herein by reference for purposes of expanding upon the present disclosure, even though some of the products disclosed therein may not be useful in the present invention.

The said esters are prepared by reacting from about 0.6 mol to about 2.0 mols of polyphosphoric acid with 1.0 mol of a condensation product having the formula R(CH CH O) H as indicated above. The polyphosphoric acid which is used is a mixture of phosphoric acids with a phosphoric acid anhydride content corresponding to about 73 to 85 percent expressed as P The effectiveness of the above hydrotropes in solubilizing non-ionic surfactants can readily be demonstrated by comparing them with a number of prior art solubilizers such as sodium xylene v sulfonate, et al. Such prior hydrotropes can take many surfactants of limited solubility into builder solutions, but none will efficiently solubilize non-ionics into alkaline builders. That is, at acceptably economic levels, none will solubilize an adequate amount of a non-ionic into the desired concentrations of alkaline builders. A comparison of the present invention with leading representatives of the prior art is given in Table I which follows:

TABLE I.MINIMUM PERCENT HYDROTROPE NEEDED TO SOLUBILIZE TRITON X-1OO IN BUILDER SOLUTIONS 1 Percent of total surfactant; remainder is Triton X-100. 2 Sodium salt pie-neutralized to pH 9.

It is apparent from Table I that far less of the octylphenoxy polyethylene oxide phosphate compounds is required to solubilize the non-ionic surfactant, Triton X100, in the liquid detergent concentrate and in the soak metal cleaning bath than is required with the other hydrotropes.

The ability of the alkyl or alkylphenoxy polyethylene oxide phosphate compositions of the present invention thus to solubilize non-ionic surfactants, such as Triton X-100, in builder solutions applies to such hydrotropes in which the ethylene oxide content varies from about 1 to about 20 units. Within this range, a very minimum amount of the hydrotrope effectively solubilizes the nonionic in hot alkaline metal cleaning baths and in built liquid detergents. This is illustrated in Table II where two systems are compared, as follows:

(1) In the first system, the customary standard for testing solubility of surfactants in hot alkaline solutions was employed. A total of 0.1% surfactant (i.e., solubilizer plus Triton X-) was dissolved in a hot 5% NaOH solution. This was done by dry blending 2% surfactants and 98% alkaline builders, then dissolving 5% of this blend in hot water. In this case the amount of Triton X100 was varied and suflicient hydrotrope was added to make up the 2% (0.1% in solution).

(2) In the second system, a liquid detergent formulation of high builder content was utilized to test the minimum amount of various solubilizers necessary to keep 5% of Triton X-100 in solution over a range of 10- 50 C. The alkali used was 18% tetrapotassium pyrophosphate, and the solubilizer was used in the sodium salt form, pre-neutralized to a pH of 9.

Either of these two systems can be used as a standard for accepting or rejecting hydrotropes which are desired for solubilizing non-ionic surfactants. It has been determined that in either of these systems a ratio of 1.5 parts of solubilizer per part of Triton X-100 is the practical upper limit. That is, to be suitable as a solubilizer for non-ionic surfactants in builder solutions, no more than 1.5 parts of the hydrotrope must be required to solubilize Triton X100. Any more than that would be uneconomical and wasteful so as not to be commercially acceptable.

With this arbitrary relative standard, any hydrotrope may be compared to determine whether it will be suitable for solubilizing non-ionic surfactants. To illustrate, Table II shows a comparison of hydrotropes, including those of the present invention, functioning to solubilize Triton X- 100 under each of the two systems described above. It will be seen that only hydrotropes of the present invention required less than 1.5 parts thereof for each part of Triton X-100. By comparison, all the other hydrotropes listed required considerably higher quantities to accomplish the same result.

TABLE II.SOLUBILIZING TRITON X-lOO IN BUILDER SOLUTIONS [A. Solution containing 5% NaOH, 0.1% total surfactant, and clear between 60-100 0.]

Minimum Maximum Ratio Sol- Minimum Percent ubilizer/ Solubilizer 1 Percent Triton Triton Solubilizer X-IOO X-lOO 1. OPErPOgHa .059 041 1.44 2. 055 045 1. 22 3. 050 050 1. 4. 054 046 1. 1'1 5. 055 045 1. 22 6. 058 042 1. 38 7. 053 047 1. 12 8. 052 048 1. 08 9. 051 049 1. 04 10. 064 036 1. 78 ll. 078 022 3. 55 12. t-Butyl phenyl EnPOsI-Ia- 09 01 9. 0O 13. Phenyl E1UPO H1 09 01 9. 00

14. Product (1) 09 01 9. 0

15. Product (2) .083 017 4. 9 16. OPE! sPOsHz/OPE7 8 068 .032 2.12 17. OPE1 tPOzHz/(OIEv 921 02151 8/2 .068 .032 2.12 18. Na xylene sulfonate 09 01 9. 00

E=ethylene oxide. 0PEx=octylphenoxy ethylene oxide (with x units of ethylene oxide) NPE==n0nylphenoxy ethylene oxide (with x units of ethylene oxide).

1 Product (1) is e phosphated non ionic surfactant prepared by the reaction of an ootylpheonoxy(polyethoxy)m ethanol and P205 by the procedure described in U.S. Patent 3,001,056. Product (2) is identical with product (1) except that the number of polyethoxy units is 11.5.

Nos. 16 and 17 are blends like those disclosed in U.S. Patent 3,004,056. No. 16 consists of 80% primary phosphate terminated and 20% unreacted non-ionics. No. 17 consists of 80% primary phosphate terminated and 20% secondary phosphate.

[3 solution containing 18% TKPP 5% Triton X400, and clear 3 important requirement is that the solution remain homotween 1050 0.]

Minimum Minimum Solubilizer (Na Salt Percent Ratio Solubi- Required lizer/Triton 1.0PEOflh N 46 0% 2. OPE5P03H 4.2 0.84 3. OPE7.5PO3H G. O 1. 2O 4. OPEmPoaI-Iz 6. 3 1. 5. Sodium xylene sulionat 9. 0 1.8

l Surfactant pie-neutralized to pH 9.

Thus far, Triton X-lOO alone among the numerous polyethoxy non-ionic surfactants has been cited to illustrate its relative insolubility in hot alkaline solutions or in builder solutions. However, it should be understood that this condition is quite general for substantially all polyethoxy non-ionic surfactants. This is illustrated in Table III below.

TABLE III.SOLUBILITY OF NON-IONICS IN HOT ALKALINE SOLUTIONS Cloud Point 1 (0.1% Surfactant Polyethoxy Surfactant in 5% NaOH) Turbid at temperatures above cloud point; if held above cloud point, solutions will separate. Accordingly, the use of these non-ionics in alkaline baths over 50 C. will be subject to the many disadvantages described above which result when the surfactant forms a separate phase at the top of the bath.

geneous and non-separating at temperatures over the range 60-100" C.

TABLE IV.SOLUBILIZATION OF VARIOUS NON- IONICS IN HOT ALKALINE SOLUTIONS Solubility of 0.1% Total Surfactant Polyethoxy Surfactant 1 in 5% NaOH 2 OIEi g, 0-100: 0

H, 0-10o CI 12. iJ-Crz-mHza-mNHEm II, 0-100 0.

1 OPEX =octylphenoxy ethylene oxide (with 1 units of ethylene oxide).

N PEx=nonylphenoxy ethylene oxide (with x units of ethylene oxide). iSolubilizer used=OPE PO Hg. Ratio of solubilizer to non-ionic Norns:

H=homogeneous, non-separating, even after prolonged storage NH=non-homogeneous; will separate relatively rapidly It should be understood that, in illustrating the mode of operation and efliciency of the present invention, Triton X (octylphenoxy polyethylene oxide with 10 moles of ethylene oxide) was principally employed as the non-ionic surfactant as a matter of convenience and since it is representative of the best surfactants of that kind. However, it is merely illustrative of the many alkoxy, .alkylamine and alkylphenoxy polyethylene oxide type non-ionics which can be solubilized by the novel hydrotropes of the present invention and this is exempli fied in Table IV above. As shown in Examples 1 to 9 of that table, the alkyl portion of the alkylphenoxy compounds can range from about C to C The alkyl portion of the alkylamine compounds can range from about C to C (Examples 11 and 12 in the table illustrating mixtures of C C The alkyl portion of the alkoxy compounds can also range from about C to C (Example 10 illustrating a C compound which is mid-way in that range).

The ability of the hydrotrope to solubilize the non-ionie surfactant in the concentrated alkaline builders is the factor which permits the surfactants to function at their maximum effectiveness under highly alkaline conditions. This effectiveness clearly is not attributable to the hydrotropes alone, for by themselves they are relatively poor cleaners, as can be seen from the data in Table V. In that table various of the hydrotrope compositions useful in the present invention were themselves employed in an effort to clean, according to a standard test procedure, steel panels which had been coated with mineral oil. Not one of them compared at all well with a cleaner consisting of an alkaline builder, a non-ionic surfactant, and a solubilizer therefor in accordance with the present invention. Such a cleaner, as shown in the table, resulted in considerable better cleaning efficiency than was obtainable with the hydrotrope alone.

TABLE V.-CLEANING EFFICIENCY OF HYDRO- TROPES VS. INVENTIVE COMPOSITION Brightstock Mineral Oil Sun 150, percent Cleaning (1), 10

Hydrotrope Minutes 1. OPE7.5PO3H2* 74: 2. OPEmPaHg 75 3. NPEwPOaHz 71 4. Cleaner of this invention (2) 100 *OI?E=oetylphenoxy ethylene oxide (with x units of ethylene oxide). I1:11PEx=nonylphenoxy ethylene oxide (with x units of ethylene oxide).

OTESZ (1) Bath run at 82 C., using 0.25% surfactant, and 5.0% base (NaOH/ Na2CO3/Na2SiO3 at ratios of 40/28.5/3l.5). (2) Octylphenoxy ethylene oxide; phosphate and Triton X-lOO in a 1:1 ratio, along with 5% of same base and other bath conditions specified in note (1) above.

From the foregoing it will be apparent that the compositions of the present invention are exceptionally useful in making it possible to utilize the superior non-ionic surfactants,,of the alkoxy, alkylamine and alkylphenoxy polyoxyethylene type, in various built alkaline detergent solutions and in hot alkaline cleaning baths. For example, as previously mentioned, one of the most important advantages of the novel hydrotropes is the improvement in soil capacity which they make possible in non-ionic surfactants such as Triton X-l00. Such surfactants tend to lose their normally high cleaning efiiciency in the presl Brightstock oil (Sun 150), min., 82 0., 5.0% base (NaOH/Na COS Na SiO3 at ratios 40/28.5/31.5).

2 90 grams rust/clay/graphite 1/1/1 plus 30 grams Sun 150.

*Octylphenoxy ethylene oxide 1.5 phosphate.

As is readily apparent from the above table, the addition of the solubilizer of the present invention has prevented a loss in cleaning efficiency of the non-ionic surfactant which otherwise would be caused by a high soil load. Presumably, the solubilization of the surfactant by the addition of the inventive composition reduces its tendency to adsorb on solid or dissolve in the oily phase, either or both being probable causes for the decrease in the surfactants cleaning efliciency when forced to function under heavy soil conditions.

Numerous other applications as hydrotropes of the novel phosphorylated surfactants, Without going outside the scope of the present invention, will readily suggest themselves to those skilled in the surfactant art. One such use, for example, is in a textile processing operation known as open boil, whose purpose is to remove sizing or dressing agents and/or natural waxes and oils from cotton. The cotton is boiled for a specified period, e.g., 30 minutes, in a bath containing 0.05% surfactant and 6.0% NaOH. The boiled samples are then rinsed in warm running Water, hydroextracted, pressed dry, and conditioned overnight at 70 F. and 65% relative humidity. Strips of the samples are then immersed one 1) inch in distilled water and the capillary (or wick) rise in centimeters measured at the end of 30 minutes. The higher the rise the better the job of removal of foreign matter from the sample. Under such a test, a non-ionic surfactant, octylphenylpolyoxyethylene (12.5 units of ethylene oxide) showed an average wick rise of 7.0 cm. By comparison, a 1:1 mixture of the same surfactant with a hydrotrope in accordance with the present invention, namely, octylphenoxypolyoxyethylene phosphate (7.5 units of ethylene oxide), showed an average wick rise of 12.0 cm. An apparent synergistic reaction is responsible for the increase in performance efliciency, for the hydrotrope alone only showed an average wick rise of 10.0 cm.

As another illustration, the present invention makes possible superior wetting action in a caustic solution 'at ambient temperatures as might be used in a desizing operation on cotton fabrics. In the well-known Draves test (5 gram skein, 3 gram hook), octylphenoxypolyoxyethylene (with 9.7 units of ethylene oxide), at a 0.1% concentration, gave poor wetting in a 7.5% NaOH solution at 25 C. It took over 300 seconds for the wetting out to take place. The surfactant was above the cloud point here. By comparison, a blend of 9 parts of the same surfactant with 1 part of the hydrotrope of this invention, namely, octylphenoxypolyoxyethylene phosphate (with 7.5 units of ethylene oxide), at 0.1% total surfactant concentration, proved to be soluble in the 7.5% NaOH solution at 25 C., and only took 21 seconds wetting out time.

In two similar Draves tests (5 gram skein, 3 gram hook), an octylphenoxypolyoxyethylene composition with 1 unit of ethylene oxide (OPE and one with 3 units of ethylene oxide (OPE both employed at a 0.2% con centration, gave very poor wetting results in a 2.0% NaOH solution at C. When exposed to these conditions for over 600 seconds substantially no wetting out occurred. Also failing to wet out in over 600 seconds were the hydrotropes employed in the present invention. Thus, octylphenoxypolyoxyethylene phosphate with 7.5 units of ethylene oxide, at 0.2% concentration and used in a 2.0% NaOH solution at 90 C., had such poor wetting action that it was useless in a bleaching operation where it was desired to have the caustic solution wet or penetrate a certain fabric.

By comparison, 1/ 1 blends of the same two surfactants, OPE (Triton X-15) and OPE (Triton X-35), respectively, with a hydrotrope of the present invention gave tremendously improved wetting results. The OPE; blend took 25 seconds and the OPE blend took 10 seconds to wet out satisfactorily.

These three illustrations involving the Draves tests are remarkable improvements which clearly indicate the beneficial effect that the novel hydrotropes have on nonionic surfactants, in accordance with the present invention.

Following are examples which illustrate the type of compositions which can be made in accordance with the present invention, all of the percentages having reference to weight relationships. The abbreviations used have the following meanings:

0PE =octylphenoxy polyethoxy (with x moles of ethylene oxide) TKPP=tetrapotassium pyrophosphate TSP=trisodium phosphate TsPP -tetrasodium pyrophosphate Example 1 A liquid detergent concentrate is prepared by mixing together 0.5% of a blend of non-ionic and hydrotrope therefor with an alkaline builder and water, as follows:

Percent OPE PO H 0.45 OPE 0.05 TKPP 37.00 Water 62.50

The concentrate is a clear, non-separating, homogeneous liquid in temperatures from to 50 C. It is useful in cleaning floor waxes from vinyl tile at concentrations of about 1.5% in water.

Example 2 A liquid detergent concentnate is prepared by mixing together 20.0% of a blend of non-ionic and hydrotrope therefor with an alkaline builder and water, as follows:

Percent OPE7 5PO3H2 18.0 OPE 2.0 TKPP 25.0 Water 55.0

The concentrate is a clear, non-separating, homogeneous liquid in temperatures from 0 to 50 C. It contains approximately 20% surfactant and 45% total solids. It is useful in cleaning metallic brown soil from linoleum at concentrations of about 1.0% detergent in water.

Example 3 A liquid detergent concentrate is prepared by mixing together 0.5% of a blend of non-ionic and hydrotrope therefor with 4.0% of alkaline builder and water, as follows:

Percent OPE PO H 0.1 OPE 0.4 NaOH 2.0

TSP 2.0

Water 95.5

The concentrate is a clear, non-separating, homogeneous liquid in temperatures from 0 to 50 C. It is useful in cleaning soil from walls.

Example 4 A liquid detergent concentrate is prepared by mixing together 10.0% of a blend of non-ionic and hydrotrope therefor with 10.5% of alkaline builders and water, as follows:

Percent The concentrate is a clear, non-separating, homogeneous liquid in temperatures from 0 to 50 C. It is useful for cleaning mineral oils from painted substrates and linoleum.

Example 5 An alkaline cleaning bath is prepared by mixing together 0.005% of a blend of non-ionic and hydrotrope therefor with 0.5 of alkaline builders and water, as follows:

Percent OPE PO H 0.0025 OPE 0.0025 N21200:; Na metasilicate 0.25 Water (approx.) 99.50

10 The bath is a clear, non-separating, homogeneous liquid in temperatures from 0 to C. It is useful in hot solutions for removing mineral oils from steel.

Example 6 An alkaline cleaning bath is prepared by mixing together 0.50% of a blend of non-ionic and hydrotrope therefor with 10.0% of alkaline builders and water, as follows:

7 Percent OPE PO H 0.45 OPE 0.05 NaOH 5.0 Na metasilicate 5 .0

Water 89.50

The bath is a clear, non-separating, homogeneous liquid in temperatures from 0 to 100 C. It is useful in hot solutions for removing paint from steel.

Example 7 An alkaline cleaning bath is prepared by mixing together 0.08% of a blend of non-ionic and hydrotrope therefor with 4.9% of alkaline builders and water, as follows:

. Percent OPE PO H 0.04 OPE 0.04 NaOH 2.00

Na CO 1.40 Na metasilicate 1.50

Water 95.02

The bath is a clear, non-separating, homogeneous liquid in temperatures from 0 to 100 C. It is useful in hot solutions for removing mineral oils from steel.

Example 8 A composition useful for preparing alkaline cleaning baths is prepared by mixing together 0.50% of 'a blend of non-ionic and hydrotrope therefor with 99.5% alkaline builders and water, as follows:

Percent OPE PO H 0.25 OPE 0.25 NaOH 39.00 Na CO 28.00 Na metasilicate 32.50

When dissolved at a concentration of 5% in hot water, a bath is formed which is clear, non-separating and homogeneous. The bath is effective in removing mineral oils from steel.

Example 9 A composition useful for preparing alkaline cleaning baths is prepared by mixing together 25% of a blend of non-ionic and hydrotrope therefor with 75% alkaline builders and water, as follows:

Percent OPE PO H 10.00 01915 15.00 Na CO 50.00 Na metasilicate 25.00

When dissolved at a concentration of 2% in hot water, a bath is formed which is clear, non-separating and homogeneous. The bath is effective in removing mineral oils from steel.

It will be apparent to those skilled in the art that the compositions of the present invention are wide in their scope, both with regard to their formulation and their use, and are not necessarily limited by the examples hereinabove disclosed.

We claim:

I 1. A composition which is useful in alkaline cleaning solutions and in liquid detergent concentrates, essentially consisting of: from about 75 to about 99.5 percent of an alkaline builder from the class consisting of the sodium and potassium hydroxides, carbonates, silicatesand phosphates, and from about 25 to about 0.5 percent of a blend of about 10 to about 80 percent of a nonionic surfactant and from about 90 to about 20 percent of a hydrotrope therefor, said non-ionic 'being a member of the class consisting of alkoxy, alkylamine and alkylphenoxy polyethoxy adducts having from 1 to about 30 units of ethylene oxide, the alkyl portion of the alkoxy compounds having 10 to 15 carbon atoms, the alkyl portion of the alkylamine compounds having 10 to 15 carbon atoms, and the alkyl portion of the alkylphenoxy compounds having 8 to 12 carbon atoms, and said hydrotrope being a surface-active composition, which contains upwards of 85% primary phosphate esters, of the class consisting of the condensation product and the salts of said condensation product of the reaction of R(CH CH O) H and polyphosphoric acid, R being a member of the class consisting of an alkyl phenoxy group, the alkyl radical of which is in the range of C -C and an alkoxy group, the alkyl radical of which is in the range of C -C and x is a number from 1 to 20; the said phosphate esters being prepared by reacting from about 0.6 mol to about 2.0 mols of polyphosphoric acid with each mol of said condensation product; and the said polyphosphoric acid being a mixture of phosphoric acids with a phosphoric acid anhydride content corresponding to about 73 to 85 percent expressed as P 2. An alkaline cleaning bath, essentially consisting of: water and an alkaline builder from the class consisting of the sodium and potassium hydroxides, carbonates, silicates and phosphates, and a blend of about 10 to about 80 percent of a non-ionic surfactant and about 90 to 20 percent of a hydrotrope therefor, said non-ionic being a member of the class consisting of alkoxy, alkylamine and alkylphenoxy polyethoxy adducts having from 1 to about 30 units of ethylene oxide, the alkyl portion of the alkoxy compounds having 10 to carbon atoms, the alkyl portion of the alkylamine compounds having 10 to 15 carbon atoms, and the alkyl portion of the alkylphenoxy compounds having 8 to 12 carbon atoms, and said hydrotrope being a surface-active composition, which contains upwards of 85% primary phosphate esters, of the class consisting of the condensation product and the salts of said condensation product of the reaction of polyphosphoric acid and a compound having the formula R(CH CH O) H, in which R is a member of the class consisting of an alkylphenoxy group, the alkyl radical of which is in the range of C C and an alkoxy group, the alkyl radical of which is in the range of C C and x is a number from 1 to 20; the said phosphate esters being prepared by reacting from about 0.6 mol to about 2.0 mols of polyphosphoric acid with each mol of said condensation product; and the said polyphosphoric acid being a mixture of phosphoric acids with a phosphoric acid anhydride content corresponding to about 73 to 85 percent expressed as P 0 the said alkaline builder being present in an amount ranging from about 0.5 to about 10.0 percent of the bath, the said blend of non-ionic and hydrotrope therefor being present in an amount ranging from about 0.005 to about 0.5 percent of the bath, and the remainder of the bath consisting of water.

3. A liquid detergent concentrate, comprising: water, an alkaline builder from the class consisting of the sodium and potassium hydroxides, carbonates, silicates and phosphates, and a blend of about 10 to about 80 percent of a non-ionic surfactant and about 90 to 20 percent of a hydrotrope therefor, said non-ionic being a memher of the class consisting of alkoxy, alkylamine and alkylphenoxy polyethoxy adducts having from 1 to about 30 units of ethylene oxide, the alkyl portion of the alkoxy compounds having 10 to 15 carbon atoms, the alkyl portion of the alkylamine compounds having 10 to 15 carbon atoms, and the alkyl portion of the alkylphenoxy compounds having 8 to 12 carbon atoms, and said hydrotrope being a surface-active composition, which contains upwards of primary phosphate esters, of the class consisting of the condensation product and the salts of said condensation product of the reaction of polyphosphoric acid and a compound having the formula R (CH CH O H R being a member of the class consisting of an alkyl phenoxy group, the alkyl radical of which is C C and an alkoxy group, the alkyl radical of which is C C and x is a number from 1 to 20; the said phosphate esters being prepared by reacting from about 0.6 mol to about 2.0 mols of polyphosphoric acid with each mol of said condensation product; and the said polyphosphoric acid being a mixture of phosphoric acids with a phosphoric acid anhydride content corresponding to about 73 to 85 percent expressed as P 0 the said alkaline builder being present in an amount ranging from about 4.0 to about 37 percent of the concentrate, the said blend of non-ionic and hydrotrope therefor being present in an amount ranging from about 0.5 to about 20 percent of the concentrate and the total of all the solids present not exceeding about 45 percent of the entire composition.

. The composition of claim 1 in which x is 7.5.

. The composition of claim 2 in which x is 7.5.

. The composition of claim 3 in which x is 7.5.

. The composition of claim 1 in which x is 10.

. The composition of claim 2 in which x is 10.

. The composition of claim 3 in which x is 10.

10. The composition of claim 1 in which x is 12.5.

11. The composition of claim 2 in which x is 12.5.

12. The composition of claim 3 in which x is 12.5.

13: The composition of claim 1 in which the alkyl group in the nonionic alkyl phenoxy polyethoxy adduct is octyl.

14. The composition of claim 1 in which the alkyl group in the nonionic alkyl phenoxy polyethoxy adduct is nonyl.

15. The composition of claim 1 in which the alkyl group in the nonionic alkoxy polyethoxy adduct is tridecyl.

16. The composition of claim 1 in which the alkyl group in the alkylamine polyethoxy adduct is dodecyl.

References Cited by the Examiner UNITED STATES PATENTS 1,970,578 8/1934 Schoeller et al.

2,213,477 9/1940 Steindorff et al.

2,730,503 1/ 1956 Pressner.

2,855,367 10/1958 Buck. t1

2,921,908 1/1960 McCune 252137 3,004,056 10/1961 Nunn et al.

3,033,889 5/1962 Chiddix et al.

3,079,348 2/1963 Boettner et al. 252137 3,122,508 2/1964 Grifo et al. 252 3,168,478 2/1965 Stefcik et al. 252-135 SAMUEL H. BLECH, Primary Examiner.

A. T. MEYERS, Examiner.

I. GLUCK, Assistant Examiner. 

1. A COMPOSITION WHICH IS USEFUL IN ALKALINE CLEANING SOLUTIONS AND IN LIQUID DETERGENT CONCENTRATES, ESSENTIALLY CONSISTING OF: FROM ABOUT 75 TO ABOUT 99.5 PERCENT OF AN ALKALINE BUILDER FROM THE CLASS CONSISTING OF THE SODIUM AND POTASSIUM HYDROXIDES, CARBONATES, SILICATE AND PHOSPHATES, AND FROM ABOUT 25 TO ABOUT 0.5 PERCENT OF A BLEND OF ABOUT 10 TO ABOUT 80 PERCENT OF A NONIONIC SURFACTANT AND FROM ABOUT 90 TO ABOUT 20 PERCENT OF A HYDROTROPE THEREFOR, SAID NON-IONIC BEING A MEMBER OF THE CLASS CONSISTING OF ALKOXY, ALKYLAMINE AND ALKYLPHENOXY POLYETHOXY ADDUCTS HAVING FROM 1 TO ABOUT 30 UNITS OF ETHYLENE OXIDE, THE ALKYL PORTION OF THE ALKOXY COMPOUNDS HAVING 10 TO 15 CQRBON ATOMS, AND ALKYL PORTION OF THE ALKYLAMINE COMPOUNDS HAVING 10 TO 15 CARBON ATOMS, AND THE ALKYL PORTION OF THE ALKYLPHENOXY COMPOUNDS HAVING 8 TO 12 CARBON ATOMS, AND SAID HYDROTROPE BEING A SURFACE-ACTIVE COMPOSITION, WHICH CONTAINS UPWARDS OF 85% PRIMARY PHOSPHATE ESTERS, OF THE CLASS CONSISTING OF THE CONDENSATION PRODUCT AND THE SALTS OF SAID CONDENSATION PRODUCT OF THE REACTION OF R(CH2CH2O)XH AND POLYPHOSPHORIC ACID, R BEING A MEMBER OF THE CLASS CONSISTING OF AN ALKYL PHENOXY GROUP, THE ALKYL RADICAL OF WHICH IS IN THE RANGE OF C6-C10, AND AN ALKOXY GROUP, THE ALKYL RADICAL OF WHICH IS IN THE RANGE OF C10-C18, AND X IS A NUMBER FROM 1 TO 20; THE SAID PHOSPHATE ESTERS BEING PREPARED BY REACTING FROM ABOUT 0.6 MOL TO ABOUT 2.0 MOLS OF POLYPHOSPHORIC ACID WITH EACH MOL TO ABOUT 2.0 MOLS OF POLYPHOSPHORIC ACIDS POLYPHOSPHORIC ACID BEING A MIXTURE OF PHOSPHORIC ACIDS WITH A PHOSPHORIC ACID ANHYDRIDE CONTENT CORRESPONDING TO ABOUT 73 TO 85 PERCENT EXPRESSED AS P2O5. 